I've not seen IT all, but what I have seen is here

Extremely slow P2Vs with VMware Converter Standalone

When running some P2Vs recently using the VMware vCenter Converter Standalone client (version 5.5.3) and was surprised to encounter extremely slow transfer rates….like 206 KB/s slow! The physical machines were several buildings away from the central datacenter so I expected some slowness but not this as these servers were really quite bland in their use case and utilization.

2. Open the converter-worker.xml file using a text editor (I used Notepad)

3. Locate the <useSsl></useSsl> tag under the <nfc> heading. By default it has a value of true.

4. Change the value to false as shown below and then save and close the file.

5. Restart the VMware vCenter Converter Standalone Worker service on the machine.

6. Execute the P2V

In my case, the P2Vs jumped from 206 KB/s to roughly 4 MB/s which was fine given the physical topology of the environment and the fact that I wasn’t in any particular hurry or time crunch (I had about a 36 hr. window) to get the P2V completed.